Improvement in cut-off valve-gears



with, which, by means of slides or equivalent vadjustable directiomfrom which a motion of HUGO BILGRAM, OF PHILADELPHIA, PENNSYLVANIA.

IMPROVEMENT IN CUT-OFF VALVEjGE/RS.

Specification forming part of Letters Patent No. 158,669, dated January 12, 1875 application filed 'April 23, 1814.

To all whom it may concern:

Be it known that I, HUGO BILGRnM, of the city and county of Philadelphia and State of Pennsylvania, have invented a new and useful Improvement in Mechanism for Operating the Valves cf Steam-Engines; and I do hereby declare the following to be a full, clear, and exact description thereof, reference being had to the accompanying drawingand-letters of reference marked thereon.

The nature of my invention consists in a device for procuring a secondary motion from the eccentric which operates the principal steam and exhaust valve,- or from an eccentric or crank having a motion coincident theremechanism, c'onverts such motion into areciprocating rectilinear motion of variable and variable extent is produced, and applied to a valve-stem or other valve-moving mechanism. I will now proceed to particularly describe the inode of making and using this invention, referring to Figure 1, which shows an elevation of the valve-operating mechanism, and 'av section ofthe cut-olf valve and steam and exhaust valves of a steam-engine. Fig. 2 shows a. section of the variable oblique slide.:

The same letters apply to the same parts in the several igures.

O represents the niain shaft of `an engine, to which the eccentric E liskeyed. The ec-f centric rod R is connected, in the usual manner to the principal steam and exhaust valve V, having passages or `ports V and V, of the construction generally used with sliding cutoff valves. The link L connects the eccentric rod R, at a, withl a slide, S, which is held by,` a guide, G. AThe angular position of this?4 guide canl be variedV and adjusted upon its fulcrnm F, by which it is attached to the steam-engine bed or frame. The end G of the slide S gears througha connecting-rod,

C, to a lever, H, by which the cut-off valve P is moved by itsr stem P'.

The operation of this invention is as follows: l When the shaft O is rotated in the direction" curve, and thereby, .through the link "L, will transmit a reciprocating motion tothe slide S. This reciprocating motion is changed in direction, and transmitted and. varied in extent, according to position of the-guide Gr to the cut-od' plate P, by the combined action of the connecting-rod 4G and lever H.

The principal steam-admission valve vV dis'- tributes steam in the same manner as a slidevalve does. in an ordinary slide-valve engine. The cut-off plate P, however, eects a closing of either of the steam-passages V or V, and interrupts the admission of steam. This interruption takes place at a 'later or earlier period of each semirotation of the' crankshaft, in proportion as the guide G is'more or less inclined orl moved in either direction of the double -headed arrow marked thereon. The amount of steam admitted during any one stroke of the piston can be. thus regulated andcontrolled.

This invention may be applied to steamvalves working upon fixed seats, instead of on the exhaust and steam-valve. f

What I claim as my invention is- The combination of the an gularly-adj ustable guide Gr, slide.s S, link L, and rod R, operatedv by an eccentric with a rod conveying motion to the cut-off valve of a `steam-engine, sub- .stantially as' shown. 

